Internal combustion engines today include electronic controls to provide optimal engine operation. One important sensor for achieving optimal engine control is a mass air flow sensor (MAFS) for measuring air intake into an internal combustion engine.
It is important that the mass air flow measurement is accurate to provide optimal engine operation. One significant problem affecting the mass air flow measurement is the turbulence in the air flow that could result in high noise-to-signal output. Prior art hydrocarbon adsorbers have attempted to address this problem by providing devices that reduce the turbulence of the entire flow field. Typically, the prior art devices use either a grid or a screen. While prior art devices reduce the turbulence of the entire flow field, they are susceptible to freezing and therefore cutting off air flow to the engine. Additionally, these devices are costly to manufacture.
Moreover, it is also important to that hydrocarbons, such as fuel, are restricted or prevented from dissipating from the engine into the atmosphere after engine shutoff. Without restrictions, after engine shutdown, gaseous unburnt fuel located upstream of the engine would typically dissipate upstream the intake manifold and through the throttle body of the vehicle. The fuel then travels through the engine's clean air duct, across the air filter and is emitted into the atmosphere. This is undesirable. Manufacturers have been challenged to provide an integral system which reduces turbulence of the entire flow field and restricts unburnt fuel at the engine from dissipating to the atmosphere.
Therefore, there is a need in the automotive industry to improve the design of devices that deliver low turbulent flow field to the mass air flow sensor without affecting significant pressure drop and restrict unburnt fuel at the engine from dissipating to the atmosphere.